[Bone metabolism and bone mass loss in eating disorders]

Eating disorders (anorexia and bulimia nervosa) are present in 1-3% of young female women. A later beginning, prolonged amenorrhea and low body mass index are risk factors of osteopenia in bulimic patients. Bone demineralization in anorexia nervosa is due to a greater resorption than bone formation leading to osteopenia, secondary osteoporosis and increased risk of pathologic fractures. Pathophysiology of bone disease includes factors as long duration of amenorrhea, deficient absorption of calcium, extreme physical exercise, 1.25 vitamin D deficiency, low creatinine clearance, increased blood and urinary cortisol and high levels of GH. Proposed treatments are nutritional improvement and weight gain (the most important), calcium supplementation, moderate exercise, estrogens, antidepressive drugs, fluoride in selected cases, byphosphonates and recombinant human IGF-1. An adequate questionnaire is essential in women with slightly decreased weight and menstrual disorders.